1. Technical Field of the Invention
This invention relates to a continuous process for the preparation of predominantly linear polyethylenepolyamines from ethylenediamine and monoethanolamine in the presence of unique thermally pelleted activated catalyst compositions having phosphorous deposited on a group IVb transition metal oxide and to the use of oxygen to regenerate the catalyst when it has become at least partially deactivated during the course of the reaction.
2. Prior Art
Heretofore, polyethylenepolyamine compounds such as diethylenetriamine, triethylenetetramine and the higher homologs have been produced by the reaction of an alkyl halide such as ethylene dichloride with an amine such as ammonia or ethylenediamine at elevated temperatures and pressures. Normally, relatively high yields of predominantly non-cyclic polyethylenepolyamine compounds are obtained from this process with varying yields of heterocyclic amines. The large amounts of energy required to produce the reactants as well as the difficult separation procedures required to recover the more valuable linear polyethylenepolyamines diminish the usefulness of the ethylene dichloride process. The hydrohalide salts of ammonia and the polyethylenepolyamine products must also undergo difficult and time consuming caustic neutralization to yield the free polyethylenepolyamines.
It has heretofore been known that phosphates can be used to catalyze reactions to produce predominantly heterocyclic rather than linear products. Thus, U.S. Pat. No. 3,297,701 teaches the use of aluminum phosphate to catalyze the reaction of ethanolamines and polyethylenepolyamines to yield cyclic compounds. U.S. Pat. No. 3,342,820 discloses the use of aluminum phosphate for the preparation of heterocyclic compounds such as triethylenediamine. As another example, U.S. Pat. No. 4,103,087 also discloses the use of aluminum phosphate catalysts for producig heterocyclic product compounds.
More recently, investigators have found that more linear products can also be obtained in a catalyst conversion. Thus, Ford et al. U.S. Pat. No. 4,316,840 discloses the preparation of polyalkylenepolyamines from ethylene diamine utilizing a metal nitrate or sulfate as a catalyst. U.S. Pat. No. 4,314,083 discloses the reaction of ethylene diamine with monoethanolamine to prepare noncyclic polyalkylenepolyamines using, as a catalyst, a salt of a nitrogen or sulfur-containing compound.
In inventions originating in our laboratories, Brennan et al. in U.S. Pat. No. 4,036,881 discloses the use of phosphorous-containing catalysts to catalyze the reaction of ethylenediamine with monoethanolamine. Excellent results were obtained when the reaction was conducted in an autoclave. However, when the phosphorus compound was supported on silica or diatomaceous earth, good results were obtained only at comparatively low conversions. Brennan et al. U.S. Pat. No. 4,044,053 is also relevant in this regard. Copending application Ser. No. 453,841 of Brennan filed Dec. 27, 1982 now abandoned is directed to an alumina phosphate-type catalyst composition wherein the novel feature is the method of preparing a catalyst from alumina phosphoric acid, ammonium hydroxide and water. Excellent results were obtained using a catalyst of this nature in batch-type reactions. Brennan U.S. Pat. No. 4,103,087 discloses the use of pelleted aluminum phosphate to prepare a di-(N,N-disubstituted amino)alkanes.
French Pat. No. 1,317,359 dated Feb. 8, 1963, discloses the preparation of granulated zirconium phosphate and its use as an ion-exchange resin. Winkler et al. in a 1966 publication [Deutsche Akad. Wiss., Berlin, Germany, Z. Anorg. Allgen. Chem. 346 (1-2), 92-112 (1966)] disclose compounds of the general formula HX.sup.v P.sub.2 O.sub.3 wherein X represents arsenic, antimony and mixtures thereof. Also disclosed are compounds of the general formula H.sub.2 X.sup.iv P.sub.2 O.sub.3, wherein X represents silicon, germanium, tin, lead, titanium and zirconium. It is shown that the group IV phosphates have cation exchange properties.
Daniel Br. Apcn. 2,092,467 published Aug. 18, 1982, modifies iron phosphate catalysts disclosed in Cavaterra U.S. Pat. No. 3,948,595 for making methacrylic acid from isobutyric acid. Daniel uses usch catalysts in admixture with a support prepared by calcining the dried powder recovered from a slurry of silica with phosphoric acid. Daniel teaches that the support is inert and that titania or zirconia can also be used.
Tawil et. al. U.S. Pat. No. 4,025,608 is directed to the reaction of a zirconium salt with phosphoric acid or a phosphate to prepare granular zirconium phosphate for use as an ion exchanger. Zimmerschied et. al. U.S. Pat. No. 2,921,081 discloses catalysts for use in the conversion of olefins that are prepared by reacting a zirconium halide with a designated class of phosphoric acids. Bates U.S. Pat. No. 2,349,243 shows treatment of hydrocarbons with a zirconium phosphate prepared by reacting a phosphoric acid with a soluble salt of zirconium such as the nitrate, sulfate, chloride or oxychloride. Stynes et. al. in U.S. Pat. No. 3,416,884 prepare crystalline zirconium phosphates by thermally treating zirconium phosphate with phosphoric acid to provide products that are useful as ion exchangers and catalysts. Dwyer et. al. U.S. Pat. No. 3,130,147 is concerned with cracking hydrocarbons using an acidic catalyst comprising oxides of aluminum, zirconium and phosphorous prepared by reacting water soluble salts of aluminum and zirconium with certain oxyacids of phosphorous and the salts thereof.
Inoue et. al. U.S. Pat. No. 4,018,706 is directed to the purification of exhaust gases using a support containing an oxide complex of titanium, phosphorous and aluminum. The complex is prepared by mixing a water soluble titanium compound such as titanium tetrachloride or titanium sulfate with a water soluble phosphorous compound such as phosphoric acid. In Holm U.S. Pat. No. 3,448,164 catalysts are disclosed that can contain titania and can be prepared, for example, by coprecipitating titanium metallates or a titanium oxide with aluminum phosphate. Rylander et. al. U.S. Pat. No. 2,824,073 is concerned with the manufacture of a titanium-phosphoric acid catalyst that can be prepared by mixing titania with triphosphoric acid to form a doughy mixture which is thereafter dried and heated.